"Parenthood" topped "Vegas" among young viewers on Tuesday to help NBC take the night in the key demographic, but it was still a CBS rout overall, thanks to the "NCIS" double-bill.

Meanwhile, ABC's new Tuesday comedy block hemorrhaged overall viewers, but held up reasonably well in the key demo, while FOX's "The X Factor" delivered weak numbers in an out-of-slot, rescheduled airing.

And "Emily Owens, MD" drooped in its second week, though with CW numbers, you never know when that's just a random statistical fluctuation.

On the the ratings...

Among adults 18-49, NBC averaged a 2.7 rating for Tuesday night, edging out CBS' 2.5 rating in the key demographic. FOX's 2.0 rating and the 1.8 rating for ABC followed in the key demo. The CW did a 0.4 key demo rating for Tuesday.

Overall, though, CBS dominated by averaging 14.77 million viewers and a 9.4 rating/15 share, far ahead of ABC's 5.0/8 and 7.46 million viewers. NBC was third with a 4.3/7 and 7.05 million viewers, with FOX's 2.7/4 and 4.42 million viewers and distant fourth. The CW averaged 1.21 million viewers and a 0.9/1.

8 p.m. - "NCIS" ruled the 8 p.m. hour overall for CBS with 17.345 million viewers and finished second with a 3.2 rating among adults 18-49, down from the show's last original two weeks ago. ABC's "Dancing with the Stars" was second overall with 12.71 million viewers and third with a 2.2 key demo rating, inching up from last week. NBC's "The Voice" was also down with 10.905 million viewers and an hour-winning 4.1 key demo rating. On FOX, "Raising Hope" (4.13 million and a 1.7 key demo) and "Ben and Kate" (3.05 million and a 1.4 key demo) were fourth. The CW's "Hart of Dixie" averaged 1.31 million viewers and a 0.5 key demo rating, basically flat from last week.

9 p.m. - "NCIS: Los Angeles" won the 9 p.m. hour overall with 16.25 million viewers and with a 2.7 rating among adults 18-49, rising episode-to-episode in viewers, but dipping in the key demo. "NCIS: Los Angeles" outdrew the combined averages for the comedy blocks on ABC, NBC and FOX for the hour. NBC was second overall but third in the key demo with "Go On" (6.41 million and a 2.5 key demo) and "The New Normal" (4.49 million and a 1.8 key demo). FOX was third overall and second in the key demo with "New Girl" (5.23 million viewers and a 2.7 key demo) and the first half-hour of "X Factor" (5.27 million and a 2.3 key demo). And ABC's comedy block was fourth with "Happy Endings" (5.93 million viewers and a 1.9 key demo) and "Don't Trust the B---- in Apartment 23" (4.28 million and a 1.7 key demo). On The CW, "Emily Owens, MD" averaged 1.11 million viewers and a 0.3 key demo rating.

10 p.m. - "Vegas" ruled the 10 p.m. hour overall with 10.72 million viewers, but dropped a solid half-point in the key demo with a 1.5 rating, good only for second for CBS. NBC's "Parenthood" averaged 4.79 million viewers and won the hour with a 1.9 rating among adults 18-49. ABC's "Private Practice" plummeted with 4.56 million viewers and a 1.4 key demo rating, mostly as a result of a weaker lead-in.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.

A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.

John - Indeed. That doesn't mean it'll get renewed or even that it'll air through all of those episodes. CBS doesn't have enough replacements not to have "Vegas" air for most of the year in some form. But a 1.5 in the 18-49 demo doesn't play outside of Friday nights.

Jobin00 - It's certainly not a good sign to lose that many viewers in a heavily promoted premiere and that's lower 18-49 than it was doing at 9:30, which isn't a fair comparison. But it's still holding its group, at least somewhat.

I assume both: A) It'll drop next week, which is bad. B) It'll get a big Live+3 bump, which is good. So... The jury is still out!

BJKRAUTK - By holding "Happy Endings" and "Apt. 23," ABC let the two NBC comedies pass through their "Shiny and new" phase and also let "Dancing with the Stars" build a tiny bit of mid-season momentum which it wouldn't have had earlier in the season. I'd say both of those things benefited the ABC comedies at least somewhat.

What the heck does ABC expect with the way they rolled out HE? If it is, in fact, a favorite of ABC they will be willing to take a little lower ratings. It is, afterall, not Last Man Standing or Malibu.

Champskins - What was wrong with the way ABC rolled it out? I saw lots of promotion during last Wednesday's comedies and during college football over the weekend and they gave the show a lead-in with 12+ million viewers. What was ABC SUPPOSED to do?

You are right Daniel... I guess I am just bitter about the way they have jerked it around in the past. I really just want people to watch this show, and though I have converted a lot of people, its just annoying that some shows can gain traction when others cant.

MGrabois - Demos mean basically everything. NBC sells on 18-49. Nothing else. Or else "Harry's Law" would still be on the air. CBS sells on 18-54 or 25-54. "Vegas" tied with "Parenthood" in 25-54 for the hour. But all of those extra viewers ultimately mean very, very little in today's TV advertising math.

CBS ordered a full season of "Vegas" and it's not mysteriously going anywhere. Yet. CBS only has one midseason drama in the can, so "Vegas" will stay where it is for now, but I wouldn't be surprised to see "Golden Boy" -- the one midseason drama -- get a tryout in that slot in the early spring and "Vegas" go to Fridays.

But all this really means is that "Parenthood" should be reasonably safe for NBC going forward, while "Vegas" isn't in immediately trouble, but its long-term prognosis is cloudy...